Question: Which protein interacts with oxytocin?
Paraphrase: Which protein interatomic with oxytocin?
SPARQL (Wikidata):  select distinct ?sbj where { ?sbj wdt:P129 wd:Q169960 . ?sbj wdt:P31 wd:Q8054 } 
Answer: Arginine vasopressin receptor 1B, Arginine vasopressin receptor 1A, Arginine vasopressin receptor 2, Oxytocin receptor